Us Weekly obtained the court documents which show that Ramsey, 29, is accusing Spitz, who appeared in the CBS documentary, The Case of: JonBenét Ramsey, for “explicitly and falsely stat[ing] that Burke Ramsey killed his sister, JonBenét Ramsey.”

In the lawsuit filed on October 6, Burke accuses the German pathologist, who worked on JFK's assassination case, of “having a disturbing history of making false statements related to the brutal murder of young girls.”

JonBenét’s unsolved 1996 murder made headlines globally, and was re-examined for the 20th anniversary of the six-year-old's death. Burke has insisted that he did not kill his sister. In an interview with Dr Phil McGraw which aired last month, he said, “I know that’s not what happened,” he said. “Look at the evidence. Or lack thereof.”

Burke's lawyer, John Lesko, has claimed that Spitz has entered another well-known case and made unsupported accusations.

"Defendant Spitz has once again interjected himself into a high profile case to make unsupported, false and sensational statements and accusations — this time accusing Burke Ramsey of JonBenét's brutal murder," Lesko wrote in the file.

"In the Interview, Defendant Spitz claims Burke, age 9 at the time of his sister's death, bludgeoned her to death. Defendant Spitz made this accusation without ever examining JonBenét's body, without viewing the crime scene, and without consulting with the pathologist who performed the autopsy on JonBenét," he continued.

Burke is seeking the $100 million for punitive damages and the other $50 million in compensatory damages, along with attorney’s fees and costs.

He is also asking that Spitz “remove and retract all defamatory statements” about him.